As a power source of an electric car, a power battery is unavoidably subjected to various faults or aging in actual use due to a complicated working environment and changing operating conditions. Once the fault is not detected or handled timely, a safety incident may happen.
Currently, there are related patents on battery fault diagnosis and battery chargers. However, these patents have some deficiencies. When an electric car is charged at night, there is still a large amount of time that can be used after the car is fully charged, but normal chargers just ignore this period of time. It is cumbersome and inconvenient for a user to purchase a battery fault diagnosis device and keep it in use.